Head gasket?

[ChristianL]

It's not on my car, but on my friend's 2.0-liter VW Jetta GT with 69k easy miles.

My friend mentioned that when her husband checked the oil recently, he found some white film under the oil cap, and wondered what it was.

I went out and popped off the oil cap on the engine, and sure enough, it had this hot chocolate/cappucino tan looking foamy residue under it.

It appears the valve cover gasket is leaking, but could this be the early signs of a leaking head gasket? The foam didn't smell like anitfreeze, and no liquid or smells are coming out of the tailpipe either.

What do you think?

[jaymond]

Give the guys over at www.vwvortex.com a hollar and see what they have to say. Good forum they got there.

[KevinJ]

I had an engine with this disease before. It’s definitely water in the oil.
Oil and water don’t mix unless you beat on them…a lot. What you get is an emulsion just as you describe.
Causes:
Blown head gasket …best case.
Cracked block…worst case.
It doesn’t take much to make what you are seeing either. You can go a long way without smalling or seeing evidence at the tail pipe (unfortunate I found out the hard way)
Either way lots of work and cash (unless they want to change the head gasket themselves).
The engine sould be flushed after the repairs are made.

[bill_keksz]

Actually - it might not be a problem.

For instance - our subie gets this & it's nothing more than condensation from atmospheric humidity, mixing with oil splashed up onto the bottom of the cap. Apparently the cap is known not to close tightly, and given its isolated location from the block (subie & maybe porsche-unique), water condenses when cold.

There are other ways for small amounts of h2o to get in the crankcase - leaky pcv valve & vac lines.

Check compression & drain oil & check that.

[djarum69]

Actually, for something like this you want to do a pressure leak-down test on the coolant system. It's possible to have a crack or gasket failure between the coolant and oil passages that doesn't change cylinder pressure.

I've seen this before. I replaced the head gasket, only to find that there was actually a crack in the block that I hadn't noticed. That sucked just a little bit.

It might be interesting to try it witht he engine both cold and warm. Pressure testing a warm engine is an interesting problem.

Ben

[ZoomZoomBrad]

FIrst step, drain the oil and inspect